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XPS-Q8 Controller
Methodology of Tuning PID's for PIDFFVelocity Corrector (DC motors with or
14.3.1.3
without tachometer)
1. Verify the speed in open loop (adjustment done using ScalingVelocity).
2. Close the loop, set Kp, increase it to minimize following errors to the level until
oscillations/vibrations start during motion, then decrease Kp slightly to cancel these
oscillations.
3. Set Ki, increase it to limit static errors and improve settling time until the
appearance of overshoot or oscillation conditions. Then reduce Ki slightly to
eliminate these oscillations.
4. Kd is generally not needed but it can help in certain cases to improve the response
when the speed loop of the driver board is not efficient enough.
To set the corrector parameters (loop type, Ki, Kp, Kd,...), use the following
functions (refer to Programmer's Manual for details):
• CorrectorType = PIDFFVelocity : PositionerCorrectorPIDFFVelocitySet(...)
• CorrectorType = PIDFFAcceleration:
PositionerCorrectorPIDFFAccelerationSet(...)
• CorrectorType = PIDDualFFVoltage:
PositionerCorrectorPIDDualFFVoltageSet(...)
• CorrectorType = PIPosition: PositionerCorrectorPIPositionSet(...)"
14.3.2
Corrector = PIDFFAcceleration
The PIDFFAcceleration must be used in association with a driver having a torque input
(constant voltage gives constant acceleration), using MotorDriverInterface =
AnalogAcceleration. (AnalogSin60Acceleration, AnalogSin90Acceleration,
AnalogSin120Acceleration, AnalogDualSin60Acceleration,
AnalogDualSin90Acceleration or AnalogDualSin120Acceleration).
Parameters
14.3.2.1
FeedForward method:
• A feed forward in acceleration is used.
• KFeedForwardAcceleration is a gain that can be applied to this feed forward.
• When the system is used in open loop, the PID output is cut and the feed forward
gain is set to 1.
PID corrector:
Note
Figure 56: Corrector = PIDFFAcceleration.
179
XPSDocumentation V1.4.x (EDH0301En1060 — 10/17)
Motion Tutorial
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